The present application is an investigation of the cognitive consequences of early perceptual processing, i.e., of the first few hundred milliseconds after the image of an object has registered on the retina. In this stage the visual system collects elements into groups and segments these groups by constructing a boundary between them. The phenomenon of texture segmentation is one of the classic problems of perception, first recognized by the Gestalt psychologists in the beginning of this century. It is only in the past 25 years that the phenomenon has come under experimental scrutiny. In the contemporary literature this process, called the extraction of shape from texture (SFT), is studied with a variety of methodologies. For the most part, these methodologies lack the power to trace in detail the temporal stages of SFT. The present application proposes a new technique which merges cognitive/perceptual research methods used in the study of divided attention and the study of texture perception: "gestalt detection" in which a brief organized image (lasting between 50 and 500 milliseconds) is embedded at an unpredictable temporal position in a sequence of carefully specified random images of the same duration. After each such sequence the subject's task is to decide whether the boundary between a region of red dots and a region of blue dots in the organized image was vertical or horizontal. By manipulating the duration of the images in such sequences, one can control the amount of time available for the SFT process. This allows analysis of the stages through which it passes and to discover how disparate types of visual information are combined. The delineation of the time course of this process may provide a baseline for the construction of norms with reference to which pathological perceptual processing can be recognized.